Bone-degrading worns key to new tailored enzymes

VIDEO: New and better animal feed products from protein-rich residual raw materials are being developed. The industry, however, lacks custom-made enzymes that break down bones efficiently.


By Andreas R. Graven


Researchers from Uni Research, in cooperation with international colleagues, are searching for solutions in the EU project ProBone.

Research leader and biotechnologist Gro Bjerga at Uni Research in Bergen, Norway, is project coordinator of ProBone.

Together with research colleagues in Germany, Spain and Romania she now intends to find the right enzymes that can do the job - and lay the foundations for new product development.

Creativity and innovation in the hunt for enzymes

So far there has been a lack of good enzymes that can break down hard materials such as bones.

However, in the future thousands of tonnes of residual raw materials, that cannot be fully utilized today, can be processed into different types of animal feed with the help of new enzymes.

By using enzymes to break down residual raw materials, they can be transformed into smaller peptides, which in turn can be processed into different products.

"We must constantly explore the possibilities and be creative and innovative in the search for the best enzymes", Bjerga says.

The search for enzymes takes place at the sea floor. This year Bjerga and her colleagues in Uni Research deposited bovine bones down to a 100 meters depth in the fjords outside Bergen.

The researchers’ goal was to attract a small marine worm that digests bones. These worms, which are about 1 centimetre long, can only be caught when they settle on carcasses and bone remnants on the seabed and begin eating them.

The researchers used large bones during the collection of the worms, because large bones are easier to find and recover. It is however residual bones from poultry that will be used in animal feed.

In Norway both regulations and controls are strict in terms of what type of residual raw materials are approved and which areas of application they can have.

Will develop a toolbox

The researchers’ starting point is the bacteria that thrive inside the worms, as they may contain enzymes that have the decomposing effect on bone mass.

“We can see that the worms break down bones, but we still do not know if it is actually done by the worms themselves or by the bacteria. We know from before that the worms secrete acid that dissolves the bone, but we also know that enzymes are involved. It may well be possible that we need to combine treatment with both acid and enzyme to succeed in decomposing bones in the laboratory", Bjerga said.

Scientists will now find the genes that encode the enzymes, and test which enzymes can break down bones.

"It will give us a so-called “proof of concept”, but it is a complicated process, and there are perhaps several types of enzymes in combination that are needed to decompose the bone", Bjerga said.

Bjerga and research colleague Antonio García-Moyano at Uni Research have stored the worms captured from the fjord in a laboratory at Marineholmen in Bergen.

"The bones were lying in the fjord for five months before we picked them up full of bacteria and worms. Later we have stored them in an aquarium at the laboratory, and we have now started the initial work on ProBone. The worms are difficult to get hold of. They bore themselves into the bones, so it’s been a bit tricky to lure them out to study them under the microscope, "García-Moyano says.

Through the ProBone project researchers want to develop a toolbox of methods for finding the bone-destroying enzymes.

Support from the meat and poultry industry

Gro Bjerga at Uni Research coordinates an international research team in the ProBone project. They have extensive and comprehensive knowledge in marine biology, microbiology, bioinformatics and biochemistry.

The other partners are GEOMAR Helmholtz Center for Ocean Research Kiel (Germany), CSIC Insitute of Catalysis (Spain), The University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca (Romania).

One of the supporters in the ProBone project is Norilia AS, a subsidiary of the Nortura group.

Norilia is responsible for selling and optimizing 150,000 tonnes of residual products. They currently have a turnover of NOK 500 million from these products.

"ProBone important for the development of custom-made enzymes”

Heidi Alverstrand is head of business development at Norilia. She says that they want to use enzymatic hydrolysis as a process to refine and add value to residual raw materials from the meat industry.

“The selection of enzymes is one of the success factors for producing products with desired sensory, functional and bioactive properties for use in high-value markets and segments. High yield and the extent of hydrolysis are also crucial”, she points out.

“The ProBone project is important for developing custom-made enzymes for building future bio-based processes and products for an increased profitability and sustainability in the meat industry”, Alverstrand continues.

In 2016 Norilia and Nortura entered into a partnership with Felleskjøpet Agri to build a new plant for the enzymatic hydrolysis of cut bone from poultry in connection with Nortura Hærland in Østfold, which is Norway's largest plant for poultry slaughter, cutting and processing.

The plant, named Bioco AS, will be completed by the end of 2018 and it is the first step in a long-term plan.

Alverstrand points out that Bioco will have a production based on industry-approved raw materials, and the process/plant is built for food approval.

Researchers are facing several challenges

While Norilia is completing its new facility in Hærland, researchers in the ProBone project face a number of challenges they have to solve in the time to come.

“The cells we examine are very small, they must be sorted and their DNA retrieved. This is one of several tasks that require that special expertise we have gathered in the project”, Gro Bjerga says.

Research colleague Antonio García-Moyano emphasizes that there are very few bacteria that can be grown in the laboratory, which is another big challenge.

"The challenge is being be able to find enzymes from all types of bacteria, not just the few that can be grown in the lab", García-Moyano adds.

Gro Bjerga and colleagues at Uni Research and IRIS have earlier developed a technology that facilitates large-scale enzyme production.

"We have spent a lot of time establishing good tools and methods, so now we are in a position where we can take in enzymes quickly and create enzymes at a higher production rate," Bjerga says.


Nov. 3, 2017, 10:42 a.m.